The goals of this program are to use biological characteristics of tumor cells as a means for improving grading of human cancer through use of more objective parameters. The object of grading tumors is to estimate the potential of the tumor for growth, invasion, and metastasis, which are important factors to clinicians in planning therapy. Tumor cell attachment to new substrates is being compared to normal cell attachment using reflection contrast microscopy. A major characteristic of cancer cells, release from density dependent growth control, is also being studied as is the role of lamellar cytoplasm in tumor cell growth. The distribution of enzyme sites on the membrane surface of human oncogenic fibroblasts has been compared to the distribution in nononcogenic cells. Some new projects characterize human cancer cell populations in archival tissues and with needle aspiration cytology. A study of endometrial epithelium and its growth dynamics in relation to endometrial hyperplasia is now underway, and a separate project on the dynamics of cellular response to cytostatic agents in head and neck cancer is in the process of activation.